SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9df9465376e1ec5068338f03c0b3f203366f4438788f3c734128c8e28bc266f2' 
  AND token = 'v9JR9jXI9Ft+ljRSBWgAugrKes1mwUBf+EHAMnMSlbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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