SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9361fbbc05a9faa12c1c4f47d0210bc84b641d15cbb5c4c24234a4d7ea143a61' 
  AND token = 'C4uLvGJG1OnJOAHCBH9i8tzlJX5pK4tWZNpTuWMxJGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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