SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47bedd49eef72918fb5311a4c5ab6385f5754971fd62f526585903b2055d9094' 
  AND token = 'aS2PmVTa2HMPnQl0nmwd7XgkmnN6LN/nYpO5GzssDpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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