SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1b7c4681b8937f5b4b69c04fce29757863f78e425ea01010c465c5bb31d09fd' 
  AND token = 'hvAoYq8G7ayvgz1AN6Hnj/XOvF6+fGAdvuCmo8xZbnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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