SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88a128a16b3e90c96db063852d6cfc7c32d4a2c97485df380228638b0090a2c5' 
  AND token = 'A7CzQRaK26SnwHygsy2iZMiUQh5d1EvT1KDHP83hq/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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