SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '643583049e2c0c542e1e571d398acf859ab917981edbd109ecba18312c154490' 
  AND token = 'WYRGNbW3Q2SIHnkwRnbtpX2j0lKZZEJN4o790Xke79I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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