SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '275d1befb718463548ea42d240235dcd7f31b45b12d89c2db45b30ed898876ad' 
  AND token = 'fKU0iHUnLVRCvJ1Bl5uUyTptQ4OjZNiBx/neCaxx/kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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