SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e26c0a942a51eda47ac1dd3418cad9a0438e033bcc19278e49586a9b28fa9dc7' 
  AND token = 'OnwNfitJ2WM1YrIPZB9hsNDHq8aQj8qnnUm8m80uDK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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