SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24801e0a87171bc7d8ddb422cf3fd43b53c9371cd607b632b770be120de4a7c6' 
  AND token = 'ihJrlfI8KoCXG7hdJDagxpSZ96VQlz/mBlCuFNOI8Gk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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