SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0de8914d3b1fd43f63ce88fc03ca5030ff2dec2788c5089fb99fcafa7c01d471' 
  AND token = 'GVKrPLB6xyZ4/RvWWBcJajzfTySaTDiloIBAJYR5Hqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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