SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c270374a82f2d126ea367497a5573cfb4320c0c7f1d50faab072508b7ae40540' 
  AND token = 'fx+4niK6/bln5cuvZ6TZwTxPED11Sui2CFK1VjopBBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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