SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bba70a10fb4391f0e326230c55a426ae18831b2ace6f28d72b87d7d29c6606db' 
  AND token = '6jHKh7SQm4faLO2RfWvcWNH6KGDSQRDyol2huQKjn5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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