SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f648c352acf3664fbe15cdd9c4c465d655696337480d811c02ce0d2cef247bd0' 
  AND token = 'gj8FmfTygnKXlg54dOFlfgKuzC8wPpfQXEbRFTrbot4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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