SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3641e3abb296832bf39dbb6b838cae5046aed39dbeeaca5dba47d04c404d561d' 
  AND token = 'AzWod4XxP8OIJTGyGt2jD/7oj6bYGXVjuOXF2tBnCR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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