SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c737796118e3ed7c68a566f3050c093251c1fc3c85d00b7e852e9abf64679e4' 
  AND token = 'ZZMFJgBrnbTXkpf2o/a7F0BjfA/xrkqmuOXX+ccPRVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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