SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc63710008d8d783e40ad8bfa938f4005a9942b51e8629657733c36f25eb13a9' 
  AND token = 'MqwVWTIEas5vFG7EXzsfoU7DZwJooZllX9Fk/CqmLuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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