SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db61998ddf584c62f5c2072574eee8783157a829856067ba3098c02dd4840474' 
  AND token = 'UwDDl8t1wa/aorjWkr4Bp9by8sj71entDPBoVfw4yxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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