SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '73fbc756ad6894f106e6319df18ebcf8f438ba5388562b1a94a38f9a57dd9508' 
  AND token = 'FDVxle0b3vmXDam4dmX5weffR/Q7cTAjnCHqyASvLOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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