SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed28e7cbbba44ccd84767119a74e123df06bb34da161967da9fd4184a77ffd54' 
  AND token = 'ZbS/YXDDCQXyJAEQGhenhPG1D5GG7CPH1CPfA8J1y74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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