SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5e1079fecd29952f1d644914342f05dfda65ed370095a515da1687df28b47166' 
  AND token = 'Oe2GIn5ePt+QR+qHxlZfUMpyeDDvg0C5t+/iExotzAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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