SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57883b7c9e7292fa4bf08ef2081f11e74bebd7e071dc9cd468b8ef261643bad7' 
  AND token = 'IKNznVR+oTPmZoztaWB3MraRAuAy5BkBxKCk8MMenRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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