SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f52e8d3037b8886f555b9385c12ce6a74778642f41b675fb3abcd3dc16b74f4' 
  AND token = 'zH7UIu0pEIO0YC2GsFuhJDAmODo8lNHXt/dUgT0TJzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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