SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcc3f12e91cbc416f78a37268c4550d17f6d9ffa07e399bc57fdc6f3f086df16' 
  AND token = 'q2wKn/TR6WLQSrQSomUTJ7LOvBBXt82msFzz7+59A+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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