Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '314664924e0a4e9c8216bf7899b3fc10c04eb6b138a8fccd1eec87fa30f7e02c' 
  AND token = 'jr/xliUvQl9jslFLtQ6kMVXzlzBmQ0Ecuz+HO+XsaCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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