SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae92b6f1dd72a7755b96faf9d605d8a1452bd0253e71d4ea5fe2d21dd4ac7f30' 
  AND token = 'm9JF/IhsnnYOVp4DMityTDvIPWGxzyK7xqRqHIWY2qI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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