SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c6861f8395339dce620ff164011ad917b2ece8f808bbcdc57a799fe989eea44f' 
  AND token = 'L7pgDnoycZoyK/RE/ijkOKZV1+7+1xWhNm+PFzkUypM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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