SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3812fe6814cbff65715d044e095b8f1fa48046dc36b795509974bc33dc4465dd' 
  AND token = 'ClYJzohGtWDQFADoouJrKLrHSHbqJ+X9WE2TrOduXY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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