SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66cf0b16431db6d0e792464b25049db3f69a78d1dbda072323081c33ddce4604' 
  AND token = 'EwwYRLA5yi9699lIN5QxhU4glynU93Zxo0UebFrgujg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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