SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '438d3b4d05c2986f75ded82067be75396d82cba4c073c15780851ea41f47f775' 
  AND token = 'jBQrbiC5QqfMEa2w6pCpLLKX4XtQ/hpBTzerh5wRd1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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