SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0acbe714bc7443db40169b6f22012a149afaaaa418c660763003b25efc06dea5' 
  AND token = 'RIcBTi3rR8KLvDMnDr7N6lfgDqa8HMjmUdhsakWQZk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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