SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbcb86056241acf80556e3663c39f11c137cfd534de44a29aa728b1b4f01bc24' 
  AND token = 'jcA2j9dlZzUC3SK3jk08boB3qcIS5qyUVck2MocD9Vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}