SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7cc98beb3150d7d3d5ea99c2a6617d3f397da4874b6fe5fe4593b4849c9e6fe' 
  AND token = '3TKa7s2l3PKn4CP2i/wLwLC0o6mTINbQDkzeWxpxb6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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