SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0dc657cd6431159ee7c51c89dd976f8af679bbe0f7f50c9b8e9489d8ebe760e' 
  AND token = 'p19vFTvc9KmDJIHqCNxKASqLYvOwhSbv+YVNTLWcVNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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