SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcdf4d69ab713ae3b1aede687058961a909ebd1e8c89a39cfef39eb1ce2f882f' 
  AND token = 'oj4gbHtpZfOF40RYQH5JppDeaJW5KdM7KX96bMcw4PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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