SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '059392cfd3df48703fa9cddb265fddc7ca606ab0ac554c2a4834066cb4cd7f76' 
  AND token = '9L//h+0S+XErBOFNq3qlmShvsY/4kQGPNfwYRwryHDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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