SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23df18b4cb2aa34adb56311b0e8ef26adbdaf3a0a25a4d9c4005be53fed88725' 
  AND token = 'bqYGspqTWkQGJhDuicxUTCy5ZKergm7Bpcwc6ZQQwRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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