SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b152a57bf69dda5539de6a3fd0d735c3f42bdfe870b41ee3475a90b826f3dd7' 
  AND token = 'YcJs8gl5JB/HxVzubgRdrPKbP11wFS+qbNtay6uBwS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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