Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0304d507eb1ddb696e7bc54b726e3353dd557357f20d97b7b210442dad95c83' 
  AND token = 'f89AnLdGboPZpcw/1D94LTmousHDma9mjd8vzI4UxUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}