SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d96c5eacc4bfd1fd68e22187dbe5c8c4c45944b8d8415828cab8da86c12de46' 
  AND token = 'VGjnfL+BL6u6EQTL/Kn7vzl/1Kphn9JX59aBfRgGzOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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