SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2721496d5730aa2e9f30f232e53ceb9dbde002db06d616667c760da769ad1f41' 
  AND token = 'Ej2h4kOBAZw6g5BwpGeq4TxKHHxVKyYJclOM6LZi9Kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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