SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a8d02b4f7a76027cfaebaa0296d8f59b3aca2fe73ee8417c4cb028ad91a59c23' 
  AND token = '0KFqWaYqRU2cG4bnOn0ccs5ajV0DcvjhAualFVSCcGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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