SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ca15971e7d919bc14af489293b4fb05d8cbe37bf0293ad861194f103967e257' 
  AND token = 'L/WgbKHjohCdhTHHycaiLpVy5H1OTOqzjd2Ap8qOyqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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