SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a436532d12eb8471a83a8598e9740e5caa2eaae83847e464d34cf74ad71b8c4' 
  AND token = 'uzBdUdYHmK2T5bW4u3jp1/dkj6GZUvg0Aqbl6v1t8eI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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