SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd963f8a86f039c4e8d259bda8841e9c737523b72c50bc053c10f2c774aeb40e7' 
  AND token = 'Fr3V7FSOsmqZymx7/jJ/gKJ+g3T9NOq/55yhD7uzlTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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