SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb8f8d27cd66a23fab0819f3c3578f77b43b38e207db3f184d46888d59419236' 
  AND token = 'uPlpG6F5cRIHe9CT+yZFZOm2KhHZhWdl/HHX/kpHIvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00842

JSON explain

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