Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e278b8afa5d283c0a7c6f5af9d3dee43f2e0636ac7e95997ea0a56b4af710327' 
  AND token = 'qjhqWdKzo7oURWRbmcDqmQnNU4D5q8uxNnyQ24c6gZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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