SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '788d37b4f25311a517f79a42b41a82746978b95f400cf27b57768223a69d999f' 
  AND token = 'faUDmW7zQyclXfB9HPUb4lRPi64ioahONNCHrxNIRP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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