SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96cff4ce6dd9103148f6e0d66321a4b37f4de7519f95089bf695835b7915e656' 
  AND token = 'hRwJiZwuB0vcX+Vhp9w6M7Tj0SnwNmKoFhyiwzMRv20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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