SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd358f1936346ab6525bd3e9833ad632c523b233c686f266f8fb9a2ee460e8870' 
  AND token = 'zcPbDMqijWQ+b5ljOPsstgPxnt9tGcNTm79nEvVkJUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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