SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d28af8a569c76cfc240d473dc257b7c70ad8ebcdae572a6ae6f1f22c95109d6' 
  AND token = '3kDV5/KycHKgPn1NSSwgDIjwAZETVDnkMjUeq/RPk/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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