SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14e92775573489f42f81c5924dee5617f4633b5a9a3725387db94affa4ece828' 
  AND token = 'abRxlrCp0+yomFHJEQFYNuQlBvJgbKUvjk3KFzCRP4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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