SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85ce26a7c17e6ebdcbaf55fdf628ff68e0dad71dad239b8d4248671051d61361' 
  AND token = 'w27SzcmHojBE/XyGZF29sX0lVVq2Azw5/CcZcvK6miI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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