SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7bebb1736122a214854d6658a18ad1a31893026370c832bd783d614409fd2c3' 
  AND token = 'bJZ+J3xUWH3WrJQ392HZKIh+LEIIFRFnqiwgwkaWdLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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