SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8884ef63f0933adfe6c2b9fec394261a9a8bce10808a226ecd1f652e7065b0ea' 
  AND token = 'h98nd7FG1i5qFRLbhcATGttiB1Pcn8FpCDkd50+10Dk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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