SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14192e17ae854648d55980c33e13b4373b83927059c5627610f9c322e4547ec3' 
  AND token = 'uPqn+qYm8U9oiRRPrgKX0fJaroG7uDhE0x7AwHk27tI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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