SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '166c0a7cd4948a15f438c18e58bf43b465d48b6dc4ff65066c08a737fae9a20d' 
  AND token = 'YZeb/DNlz5YUwG1tozweVlzd3R2UsbYcwy+6afkQGbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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