SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2c98271edd0f4cac8617284e539ef2f66508cd958441d4902b4850a90074fc0' 
  AND token = 'aM62AdvZ/hSYSHUrIF3GlivW4bQZlIIgwq6RpJV+wo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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