SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a914d8c482f05b3b427d08329d59dcb79705c068a0a8b4fbe64965ac3d02f050' 
  AND token = 'dLPbI/JvbK822SPG+ihgRQPnNvyVq3qlc6skEus8HAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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