SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e50ae7f22d32f5cc807483db48fd8896566f67ebecbb9a7737e008e41ba025c' 
  AND token = 'M7I256pDV0TqnBYxtdL+CpApYsZB18kxVcqvqIbW5vI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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