SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c254b2df60655ef4ad07291d62a2746c64e09e6214beb55945ba1683832b9418' 
  AND token = 'j5up0U/eR1v7DGUxUWi5sD/HNNAgSOK3J9EIlMUPa/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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