SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ed738a40dbf55f5c7e2a52ff82551576ca250e6fe5c3becd8f0707ebaab8260' 
  AND token = 'uCzzGs4SXQ5ahCI7A8ZS/UxthccRxDOKycs4bG8Tx/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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