SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7377aaa902275ba6f3b06ca80931a526790f4b6e3a06b0acdc3b61f82171dc29' 
  AND token = 'hTMjLwf/3GK0uwDUuF7iff+/WKaDdynpJr9COxA9nOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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