SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '863e9facaecfed7085fdf46a8599877e785957133fea9500c98a001d2111f63d' 
  AND token = 'Uv8p4Nqhz+32WB13D5ZHdIqSfxCx9DUOINY4RUuVZLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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