SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f013af846328c81901a0bfd0af70b74cbd37d077492051fa7304109f0343c79' 
  AND token = 'spO76zU7dXC/5kg83uyzAxMjZhxBis39iuI1agRsPsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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