SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f88acfdde831ba9aa177e94729dd0707aa0d21757e774440e8fe1f70711a41b' 
  AND token = 'q8RbCVIvrtktY7RyVyEYZkU3tzQDuqJFruQ10K/Ya5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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