SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f4b90efea85f584568e8416523d824468c913abd9227a50916d78574dcc2f06' 
  AND token = 'wl5REypCdaXo/rRSFTBdPZOCptb8TbejxABl4xLsaHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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