SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6227326b39a25eeff74a2c1ce808625d0788cd070f5077f8333f247fb66cfd8' 
  AND token = '8Kb8GjoYa4K5F1zFLWmKW7JShGYFanR2fE+UU9vih8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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