SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '331ca05b53f1ebdd5b256e914e1cfc777ca915219d9f1154ff96528ac6bd239e' 
  AND token = 'bho4dwTCDdgY34/yRS9MQy7HADxvo2cZRPkWG0KR9dw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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