SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '450cf04fd15f4db05f5ffe02e7fd22a9c9702b3a9e24e527897d617dfd43edcd' 
  AND token = 'EmohexZuObOsklliAxvVVkUnbTSzcrvaQL7I2pMZqNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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