SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1144883e7e6d77177cd09bbd5c0e24cc198719954cb5f367f18640ab123d8673' 
  AND token = 'MgbOCBs+I9lyb7c3WPWO5D13k5WGfMdp7cBd+16hG1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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