SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c60e4b9d5365a55936c579fa6776e9f9b523007f4b7b92cb339924fa71efc803' 
  AND token = 'BE80nNDCXBLExuAohCDzhPrLPCBVPjpHA5FFV1+Pugg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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