SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a94a14e99bca610c06b433fa0f3db8961c6553079e6c5d3b22843df247f99db5' 
  AND token = 'ysoQ2sKH/xDL74nGYDMMgr6K1HXIHOav0xqqs/cRgbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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