SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac3eee5357bcbf3be12090bb2ddb9e6a79635116c86e875bfc5fc7220ae3250e' 
  AND token = 'CqqmPYfWzOxaCxgrY4jYFSY/QUeLc+laQINb+pYiWU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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