SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd74d5da29cc0a45c6feacfe37239bfa150bd43fa1007856dd9232d66935c3027' 
  AND token = 'E1cGz8qD+soMQ7Tg/5UoXht/FSmi3x4RgHPqDWe9qNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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