SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ac2fc388ae441009df7fb3a8d130074fc4b74e6fa7913b1b8685d1236c7ddd5' 
  AND token = 'Pl1VEYqVwUHWAgod4i3yTjdGClp4/jY2CjvzrOGauaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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