SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8f185443be03b476a9e4ded5aa04447f8e78adff3640ca9c3e88a5627bc5406' 
  AND token = 'vhxittUYx16BeVPtT6ZkHGN5CztJCND+dT3ZyG6GKtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}