SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '846e805dff4105ec929db5fb6a2c93cda610565ed30e38cc1718dfc68fc1a625' 
  AND token = '9qTvKWEBsPL07rEBcoe/CcLDKxxvwssfEl6Cte3DHyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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