SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e46bbf7ec5afd317378a3e88c494f6610631ba778013789c6c5d8cdef3e1d7e' 
  AND token = 'IkdOxt/lCkRctb1JlyjFmub+QqUxvFtOliVkHasC3gU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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