SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd953d5e0c2947183faacb4ca5b448f11ceb97faff9a5a63887b1f8d4995f6253' 
  AND token = 'CNvv36EPtjRgqrpXpUfe25BuA6OJRnFZuykMVBSKT28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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