SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a86c81c6ec89cc5d7c0cb3fdd52544b8d0a1589bcb65bd0936c71e78f8aab17' 
  AND token = 'tfPhN9Y4JIjqThgm0+WrEUF3OVkrGQxsRQ70otHpF+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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