SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1978a30b5637243defd8d5c69410743346c42afc0cc69da46e32e386d146395a' 
  AND token = '2JGCSfMrybLSRzPSCU7FANryYbljuit61Qia7a49gwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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