SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d800b8d17d779965b6de9d5a592eb4fe6e466284833c7fafc5ec459660832e6' 
  AND token = 'KQas8OQXVyVlVRQJva+2NgQSz6qG9wroJQkVmC30gA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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