SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24010dd1715891ff948349207c71f094430acc4843dfebeada337d3225622f6a' 
  AND token = 'NFJ3zsLFnDwngRoW5W1Qo238gGpwLJT0z4/VWrfg3iY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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