SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfec1ee42eb89a7089a9815e90257925e1c4f567431357b0dc89b1f66d57f81c' 
  AND token = 'VMi0dR3mMfpMaG1rdY+w2PrXU9N8HN4LwmTn95LmLwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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